DESCRIPTION. The AZ (24) is mechanical impact fuze with a safety arming period of 10 seconds provided by the clockwork gear train. There are two striker system incorpora-ted: An inertia striker system to operate on impact and an anti-rupture striker to func-tion in case there is any distortion of bomb of fuze pocket on impact. (See fig. 136.)

The two striker system are located at opposite ends of the fuze separated by a flash channel approximately 260-mm long.

There are two pieces of wood secured together by 4 staples to form the packing bet-ween the two sections of the fuze. The only difference between the (24) and (24) A is in the metal covering around the wood packing. The (24) A has the metal covering and the (24) does not.

OPERATION. On release from the aircraft, the cover and safety pin are pulled away from the fuze allowing the detent bar to move across. The speed of this movement is gover-ned by a clockwork gear train.

After 10 seconds the detent bar has moved sufficiently for the spring loaded plungers A and B to move into the recesses in the detent bar. The movement of plunger A releases and arms the striker system and the movement of plunger B releases a shutter which in turn allows the spring-loaded detonator to move along the channel and position itself opposite the percussion cap of the bottom of the fuze. The percussion cap is part of the antirupture device.

On impact the inertia striker pellet pierces the detonator cap, the flash from which igni-tes the powder pellets. This second flash travels through the channel to the spring-loa-ded detonator. This detonator sets off the gaine and main charge.

On impact should there be an excessive distortion of the bomb or fuze pocket, the striker in the antirupture device is forced by the ram into the percussion cap. The flash from this cap ignites the detonator, which in turn sets off the gaine and main charge.

Figure 136 – (24) A Mechanical Impact Fuze with Antibreak-up Switch